The overall objective is to increase our knowledge about the circulation and vascular hemodynamics in oral and related tissues of an animal model. The specific aims involve a multi-technique approach to: 1) determine local blood flow, tissue O2 consumption and CO2 production, bone marrow, intracranial and dental pulp pressures, and other related variables; 2) clarify contradictory findings concerning circulation in oral tissues, 3) thoroughly assess fiberoptic and LED photoplethysmography as well as an isothermal flowmeter; and 4) expand our computer capability. The indicator technique involving a diffusible tracer (86 Rb), H2 gas and two or three different radioactive microspheres, will provide quantitation of local blood flow. The submarine respirometry approach will be used to determine tissues O2 consumption and CO2 production. The pulpal pressure determinations will involve a tonometric approach. The achievement of our objectives will furnish further knowledge of basic physiology and new ideas for future studies.